Wireless telegraphy.



L. F. FULLER.

w'laELEss TELEGRAPHY.

APPLICATION FILED APRf 2|, i913.

will,

Patented Apr.11,1916. p

vINVENTOR. WITNEssEs.-

L, E FULLER L 614km/ BY a v 7 :i

' o? ATTORNEYS.

UNITED sTATEs PATENT f oEEicE.

LEONARD F. FULLER, 0F PALO ALTO, CALIFORNIA, ASSIGNOR T0 FEDERAL TLEGRAPH i i REISS COMPANY, 0FV SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

' WIRELESS TELEGRAPHY.

Application ined -Apri 21, 1913. seriai No. 762,475.

T 0` ZZ 107mm z't may concern K lie it known that I, Lioxann F. FULLER. a citizen of the. United States. and a resident of lalo Alto. county of Santa Clara. State of ("alifornia. have invented certain new and useful Improvements in 'ireless 'l`elegraph v, of which the following is a speciication.-

The invention relates to improvementsin wireless telegraphy and yespeciallyfto improvements in the transmitting circuit.

The object of the invention is toA obtain a higher antenna current with a given input than has been heretofore obtained.

Another object of-t-he invention is to reduce the. resistance of the antenna circuit, thereby increasing the antenna current.

Another-object of the invention is to provide means for obtaining sharper tuning than has been heretofore practical.

The inventionv possesses other advantageous features. which, with the foregoing,

will be set forth at length in the following description where I. shall outline in full that foi-iii of the invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. 'lhe noveltyY of the invention will be included in the claims succeeding said description. From this it will bey apparent that. I do not limit i`nyself to the showing made by said drawings and description. as I may adopt many variations of the said invention as expressed in said claims.

Referring to saicl tlra\\'ings: Figure 1 is a diagrammatic representation of one form of the transmitting cii'cuit of my invention. Fig. 2 is a diagrammatic representation of a modified form ofthe circuit. I4`ig.'3 is a diagrammatic representation of theclosed circuitforni of my invention. Fig/ is a diagrammatic representation of another modified form of kthe circuit.4

In wireless telegraphy transmitting circuits, .a certain amount of energy is not' is supplied by the conductors S--i connected In' the forms of the inventionfshown inFigs. 1 and 5f v 2, one side of the arc is` grounded by the Connected to the other side of the arc is a conductoi' 6 connected to the 'l' antenna 7 and including in circuit in series g a capacity, preferably -in the form of aV variable condenser 8 and a variable induc Shunted around the variable vconisy a circuit 11 con? tain1ng a capacity, `preferably' in the 'form ofa. variable condenser 12.r The condenser 8 i y may be. arranged as shown in conductor 6,k or it may be placed in conductor between the arc and the, point of connection of cii'- f cuit 11, or two condensers may be used, one' Y in eachcf the positions stated.' 'Ihefunc-4 tion of the condenser S is to `produce a f voltage to cause the current to passthrough the shunt circuit '11. which contains very 'i to any suitablev source of power.

conductor tance 9. denser 8 and the arc 2 small resistance and iiiductance, and charge the condenser 12.

impedances, the IgR losses of the arc areac.- cordingly reduced.

the are, the ohiuic drop through the arc and value is independent of Wave length and the shunt circuit is in no wise a tuncdcircuit. 'This makes this connection verv flexible" where .a rapid change of waver is desirable.;v

It is an important feature ofthis invention that the inductance and resistance :of the shunt circuit 1l be kept a minimum, as f' otherwise the circulating currents through'Y 'it will not be wattless, as is desired, but Willl` have a power factor of appreciable Valiie. In a circuit in which the arc is more or .less f unstable and inclined t-o set upfseveral irregularly dispersed frequencies, this circuit Y. will greatly reduce this tendency, increase put all of the "f' n the sharpness` of tuning and radiated energy in one, Wave.

In einployingthis system in practice,fi

of 50% in the antenna current. over the sysrateatea Apr; 11, 1916.` .gf f' w Since the impedance of" the shunt circuit is inuch less than that of the arc circuit on, which it is shunted," 'and f since the antenna current dividesthrough the arc and shunt circuits inversely as their i.

The capacities of the condensers to be employed dependupon the capacity of the antenna. the power fed t0 tem in which the antenna current passed entirely through the arc. Using the same installation and doubling the capacity of the condenser 12, I have obtained 100 per cent. increase in the antenna current. The capacity of the condenser 12, however, has a certain maximum critical value above which it fails to aid in boosting the antenna current. Using a 50 K. IV. arc I have obtained an increase in antenna power of 71 per cent. over the system in which the total antenna current passed through the arc. The eiiiciency of the systemhas been .further increased by about 11 per cent., when the 50 K.- IV. arc was in use, by means of the circuits shown in Fig. 2 in which a circuit 18 containing resistance 14, preferably variable, and an inductance 15, preferably variable, is shunted around the condenser 8. If this circuit be tuned nearly into resonance with the oscillations in the main antenna itl will have-a very high reactive voltage drop across it and-will, therefore, force a still greater per cent. of the antenna current through the shunt circuit 11. The resistance of the circuit 13 is comparatively large, allowing a very small current to pass therethrough, so that little energy is consumed therein.

It should be noted that the circuit shown in Fig. 1 raises the antenna power by reducing the lresistance of the antenna circuit while the circuits shown in Fig. 2 increase the antenna power by greatly reducing the energy losses in the arc.

The modification shown in Fig. 3 operates in the same manner as that shown in Fig. 2, with the exception that the arc circuit is inductively connected to the antenna circuit through the transformer 1G, preferably variable, instead of being directly connected thereto. In this system a condenser 18 must be inserted in closed circuit, to produce the capacity effect of the antenna in the open circuits.

Signaling is usually accomplished by varying the frequency or the wave length of the .radiated oscillations` by varying the inductance in circuit. In the present instance I have shown a key circuit 17 adapted to shunt one or more turns of the inductance 9 or the primary of the transformer.

I claim:

1. In a transmission system for wireless telegraphy, a grounded conductor, a source of electrical oscillations. a capacity and indu'ctance in series on said conductor. and a substantially inductionless circuit containing a capacity shunting said first named capacity and the source of oscillations.

2. In a transmission system for wireless telegraphy. a source of electrical oscillations, a grounded conductor associated therewith, a capacity in series with said source, and a substantially inductionless circuit containing a capacity shunting said first named capacity and said source.

3. In a transmission system for wireless telegraphy, a source of electrical oscillations, a grounded conductor associated therewith, an Vinductance and capacity in series with said source, a capacity in shunt on said source and first named capacity, and an inductance in shunt on said first named capacity.

i. In a transmission system for wireless telegraphy, a source of electrical oscillations, a grounded conductor connected thereto, a capacity and inductance in said conductor. a circuit containing capacity shunting said source and first named capacityl and a circuit containing inductance and rc sistance in shunt on said first named capacity.

5. In a transmission system for wireless telegraphy, an arc, a grounded conductor as sociated therewith, a capacityv and inductance .in series in said conductor, a circuit containing capacity shunted around said are and the first named capacity, and a circuit containing resistance and inductance shunted around said first named capacity.

6. In a transmission system for wireless telegraphy, a source of electrical oscillations, a grounded conductor associated therewith, an inductance and capacity in series with said source, and a circuit shunted on said capacity and source` the impedance of said shunt circuit being less than the impedance of the circuit shunt/ed.

7. In a translnission system for wireless telegraphy. a source of electrical oscillations,

la grounded conductor associated therewith,

an inductance 'and capacity in series with said source, a circuit containing capacity in' shunt on said source and rst named capacity. and a circuit containing resistance and ind uctance shunted around said first named capacity, the last shunt circuit being out of resonance with the oscillations in the an tenna circuit.

8. In a transmission system for wireless telegraphy, a grounded conductor, a source of electrical oscillations. a capacity and inductance' in series in said conductor. a substantially inductionless circuit containing a capacity shunting said first named capacity and source of oscillations and means for varying said inductance.

In testimony whereof, I have hereunto set my hand at l@an Francisco` California. this 7th day of .\pril 1913.

LEONA RI) F. FIILLICR.

In presence of- I-I. (i. Pnos'r, M. La (loN'rE.

copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. 0." 

